Field of the Invention
Exemplary embodiments of the present invention relate to a touch screen panel and a method of manufacturing the same.
Discussion of the Background
Touch screen panels are devices that are touched with a finger or a pen to input data. Touch screen panels are divided into resistive touch screen panels, capacitive touch screen panels, optical sensor touch screen panels, and the like, according to the operation principle thereof.
Resistive touch screen panels use the contact between electrodes caused by a pressure equal to or greater than a threshold pressure applied thereon. Capacitive touch screen panels use a change in capacitance that occurs when a finger touches the capacitive touch screen panels.
Resistive touch screen panels and capacitive touch screen panels each comprise a separate touch panel in addition to a conventional display panel that has an upper substrate and a lower substrate. However, this structure deteriorates overall optical characteristics and increases the thickness of display devices.
Therefore, touch screen panels having optical sensors formed in a display panel are being developed. However, when optical sensors are formed on an upper substrate of a display panel, external light is reflected by the optical sensors, switching thin-film transistors, which are connected to the optical sensors and transmit detection signals to a sensing wiring, and metal wiring, which is used for the optical sensors and the switching thin-film transistors. As a result, optical characteristics deteriorate in a bright room. For example, a contrast ratio is reduced.